摘要 |
Portable terminal MS downloads coupon data and public key KEYP2 of IP server 20 from IP server 20. Service terminal T obtains from IP server 20, a server certificate to which a digital signature is applied by secret key KEYS2. One to one local communication by infrared radiation is performed between portable terminal MS and service terminal T. At this point, portable terminal MS decrypts a server certificate by utilizing public key KEYP2 of IP server 20. Then, portable terminal MS communicates specified data after authenticating the identity of service terminal T. <IMAGE> |